Countdown On for Thursday Night Space Shuttle Launch

No technical issues should affect Thursday’s planned launch of Space Shuttle Discovery, NASA Test Director Jeff Spaulding announced during a countdown status briefing this morning at Kennedy Space Center. Discovery’s onboard cryogenic tanks were loaded last night, and software loads and verifications are underway today, along with the power-up and checkout of ground communication systems. The launch pad’s rotating service structure is set to be retracted at 12:30 a.m. EST Thursday, and loading of Discovery’s orange external tank will begin around 11:40 a.m.

“Discovery and her crew are set to embark on one of the most complicated missions ever performed, and I’m happy to say our vehicle is ready,” Spaulding said.

Asked about the issues raised Tuesday evening regarding the mobile launcher platform power surge and adhesive on a reusable solid rocket motor, Spaulding replied, “We expect all issues to be cleared by the time we go into the L-1 MMT meeting today.”

Joining Spaulding at the briefing were Debbie Hahn, STS-116 payload manager, and Kathy Winters, shuttle weather officer. Discovery’s payloads are ready for flight, but weather remains a major concern.

“Tomorrow we are expecting a frontal system to come into the area, and that is going to bring in a lot of cloud cover,” Winters said. “We did increase our probability of weather prohibiting a [Kennedy] launch to 60 percent.”

The forecast indicates the possibility of isolated light rain and low clouds in the area at launch time. Weather is also a concern at a contingency landing site in Istres, France. Tail winds there may increase and pose an issue as well.

In the case of a 24-hour delay, the forecast isn’t much better: there’s a chance the winds at the launch pad or Shuttle Landing Facility could exceed limits, bringing the chance of weather prohibiting launch to 70 percent. A 48-hour delay would leave the launch team with a 60 percent chance of weather preventing liftoff.

“Weather starts getting more promising as we get into Sunday or Monday evening, but Tuesday looks the best right now,” Winters concluded.

The STS-116 mission is the 33rd for Discovery and the 117th space shuttle flight. During the 12-day mission, the crew will continue construction on the International Space Station, rewiring the orbiting laboratory and adding a segment to its integrated truss structure.